jquery遍历元素的位置

Question

for (i=1; i <= 3; i++) {
   var larg = $("parallax-section-" + i).find('.testo-parallax').width();
   var largPa = larg / 2;
   var largParallax = "-" + largPa;
   $("parallax-section-" + i).find('.testo-parallax').css("margin-left",  largParallax);
}

HTML

<section class="slide parallax-section-2" >
   <h6 class="testo-parallax">Il weeb asdf asss dasdf ss.</h6>
</section>

CSS

.testo-parallax {
   font-size: 80px;
   color: #fff;
   font-weight: 600;
   position: absolute;
   top: 50%;
   left:50%;
   margin:0;
   padding:0;
   margin-top: -40px;
}

我想从左边的文本（.testo-parallax）开始居中（.parallax-section）。我有三个部分，我想检查宽度，以获得半宽的边距 - 左和 -